1. Field of the Invention
The present invention relates to a paper-making screen apparatus. More particularly, the present invention relates to a paper-making screen apparatus having an improved screen, in which the interval between a first end plate and a second end plate is kept by interval keeping members, and further, ends of rod-shaped members are held by a first and second end plates.
2. Description of the Related Art
There is available paper-making screen apparatus in which a screen is formed by annularly arranging a plurality of rod-shaped members between a first annular support member (first end plate) located on one end side and a second support member (second end plate) located on the other end side (for example, U.S. Pat. No. 5,605,234 and U.S. patent application Ser. No. 08/741,718).
In U.S. patent application Ser. No. 08/741,718, an interval keeping member is provided between a first annular supporting member and a second annular supporting member to keep an interval between the supporting members, and further, ends of a plurality of rod-shaped members annularly provided are held by and between the first supporting member and the second supporting member. An end of the interval keeping member is secured by welding to the first supporting member, and the other end of the interval keeping member, to the second supporting member, respectively (see FIG. 6 of U.S. patent application Ser. No. 08/741,718).
In a screen disclosed in U.S. Pat. No. 5,605,234, ends of rod-shaped members are individually secured by welding (see FIGS. 6 and 9 of U.S. patent application Ser. No. 08/741,718; while screws are used in FIG. 9, ends of the rod-shaped members are secured by welding to the first supporting member and the second supporting member, respectively).
Particularly when securing by welding, welding is carried out while applying a force by a press to ensure a state of firm fixture. This leads to a low operability, making it difficult to manufacture the same, and in addition, welding strain causes a deformation, and hence deterioration of screen performance, not permitting achievement of uniform intervals between adjacent rod-shaped members. When replacing damaged rod-shaped members after assembly, furthermore, it is necessary to grind off welded portions with a grinder, this posing a problem of a very poor operability.
The present invention has an object to provide a paper-making screen apparatus for solving the problems as described above.